This invention relates to a substrate support for supporting substrates during processing.
In the fabrication of electronic circuitry, semiconductor, dielectric and conductor materials, such as for example, polysilicon, silicon dioxide, and metal containing materials, are formed on a substrate, and etched to form features such as gates, vias, contact holes and interconnect lines. The materials are typically formed by chemical vapor deposition (CVD), physical vapor deposition (PVD), oxidation and nitridation processes performed on the substrate. Thereafter, in typical etching processes, a patterned mask of photoresist or oxide hard mask is formed on a deposited material by photolithography and exposed portions of the substrate material are etched by an energized gas.
During the forming and etching of materials on the substrate, the substrate may be supported in the chamber by a temperature controlled substrate support. The temperature of the support is often controlled by circulating a fluid in conduits in the support. However, sometimes, the fluid leaks out from the conduits during processing of the substrate. Such fluid leakage changes the temperature of the substrate resulting in improper processing of the substrates. Fluid leakage can also cause the gas pressure and composition in the chamber to change by vaporizing and mixing with the gas. Leakage of fluid also leads to undesirable chamber downtime to repair or replace portions of the chamber corroded by the leaking fluid.
Thus, there is a need to inhibit the leakage of the fluid passed through the support. There is also a need to quickly detect any leakage of the fluid to alert the chamber operator so that processing of the substrates can be halted.